U.S. Pat. No. 3,734,743 and U.S. Pat. No. 3,891,773 summarize the extent of publicly known prior art with regard to the culture of sour dough bacteria. The disclosures of both of the above referred to patents are incorporated herein by reference. The procedures for culturing sour dough bacteria according to these prior art processes do work for growing Lactobacillus sanfrancisco bacteria. However, the procedures of these patents do not use inexpensive ingredients, they do not teach how to achieve high cell count in cultures and they do not provide any teachings of techniques which enable inexpensive storage of the harvested bacteria for long periods of time without loss of activity.
The present invention evolved from a prior art procedure developed by the inventor of the present invention. This prior art procedure was used commercially and because it formed the basis for the improved invention herein, is set forth in full: